(a) Field of the Invention
The present invention relates generally to a battery charger, and more particularly to an enclosed battery charger.
The development of dry batteries has been for quite a long time. This kind of storing electric power within a columnar body to supply power at times of necessity does facilitate our use of certain electrical appliances. It breaks through the restriction of conventional power source and provides considerable convenience in our daily life.
There are devices available in the market for holding storing dry batteries. The placement and keeping of dry batteries are often connected with the electrical appliances or products used, such as toys, portable radios, hand torches, etc. There are also some dry batteries which are stored separately from the electrical appliances used. In addition, there are also battery chargers for keeping rechargeable nickel-cadium batteries, which may be recharged when the battery chargers are connected to an A-C electric power source which is rectified to lower its voltage.
(b) Description of the Prior Art
The common major characteristic of these battery storing devices is that the electrical circuits in most of them are connected in series due to the voltage required. Take the known battery chargers as an example, the batteries are usually arranged two in a set, but connection of the circuit is in series.
As shown in FIG. 1 of the drawings, a conventional battery charger consists of a seat 10 provided with a couple of negative springs 101 and a couple of positive plates 102, each of which being connected by lead wires. The batteries are placed in a compartment 103 of the seat 10. Both lateral walls of the compartment 103 integrally extend upwardly to form a plurality of corresponding curved wings 104, which has a curve corresponding to the curve of the batteries for preventing the batteries from slipping out. However, there are a number of drawbacks when this kind of battery charger is used in certain electrical appliances and products. For instance, the batteries are not effectively ensured against contact with liquid, which may easily cause leakage or short-circuit of the batteries. The curved wings 104, which are made of elastic material, may not effectively prevent the batteries from slipping out. But if the curved wings 104 are configured to be longer in size, it will be very inconvenient to place the batteries; if they are made shorter, they cannot prevent the batteries from slipping out. Additionally, the lead wires may cause short-circuit. If the batteries are included in the battery chargers when they are delivered ex factory, the lead wires may get connected and cause short-circuit during transportation and storage, so that all the battery power is exhausted.